Five Copa Libertadores matches you can't miss this week

Internacional needed a come-from-behind effort to beat Emelec when the two clubs met in Brazil.

Approaching a mini pause due to the upcoming international break, the Copa Libertadores has a big week coming up, with 28 of the 32 teams in action.

Some are playing their third of six group games, while most are playing their fourth. This is the time, then, when qualification for the knockout stage starts to be defined. There are some huge matches coming up in the next few days. These are the five to pay attention to.

Tuesday, Group 8

Sporting Cristal (Peru, 5 points) vs. Racing (Argentina, 6 points)

Last week these teams met in Argentina, where Cristal's 2-1 win was the shock result of the competition so far. Racing had won both their opening games in fine style. Cristal were unbeaten, but had drawn both games from a winning position, and seemed unlikely to have the mental strength to cope with a raucous Racing crowd.

True, Cristal's win came with a soft -- or dubious -- late penalty. But they were full value for their win. Coach Daniel Ahmed pulled central midfielder Josepmir Ballon into a back three, ensuring that Cristal were never outnumbered defensively when Racing went at pace -- while at the other end the speed and incisive runs of little Irven Avila proved a constant headache for the Argentine defence.

This week, Racing will hope to cause Cristal plenty of problems with the return of veteran centre forward Diego Milito, who missed last week's match through injury. Milito was in magnificent form in the first two games. The headlines went to his strike partner Gustavo Bou, who hit a pair of hat tricks. But more than an individual effort, his success was the result of good collective play, in which the intelligence and technique of Milito were crucial.

Does his return, then, mean that Racing slip back in the groove, or can Cristal, their tails up, pull off another surprise? We'll find out Tuesday.

Ex-Inter Milan forward Diego Milito has been in fine form for Argentina's Racing this campaign.

Wednesday, Group 1

Santa Fe (Colombia, 6 points) vs. Atletico Mineiro (Brazil, 0 points)

This is the third group game for rivals with contrasting stories to tell. Santa Fe, hugely impressive, are 100 percent, sporting two wins from two games. Atletico have lost both their matches and been very poor doing so. And now they face their most difficult group opponent, away at the altitude of Bogota (relatively mild but never enjoyed by Brazilian teams) in circumstances where another defeat will leave them very close to elimination.

The problem here is that Atlletico's away form -- when they won this competition in 2013 and in lifting the Brazilian Cup last year -- has been very poor. They have consistently relied on heroic comebacks in front of their own fans. Now, then, they have to do it the hard way.

The good news is that recent Argentine acquisition, centre-forward Lucas Pratto has recovered from injury and should be fit to play. The bad news is that Santa Fe, with a promising pair of centre-backs and an interesting attacking quartet, are better than anything the Brazilians have faced so far in the competition.

Wednesday, Group 2

Sao Paulo (Brazil, 3 points) vs. San Lorenzo (Argentina, 3 points)

With three former champions and only two places available in the knockout stage, Group 2 was immediately given the inevitable "group of death" tag. Corinthians of Brazil seem very much alive, having beaten both these sides before facing two upcoming games against Danubio of Uruguay, the weakest team in the group.

These two teams, then, are effectively disputing the right to qualify together with Corinthians. Reigning champions San Lorenzo can take more heart from their defeat to Sao Paulo's big local rivals. Corinthians' 1-0 win was not a fair reflection of the play in a match in which San Lorenzo often looked a better side than the one which lifted the trophy last year. But Sao Paulo have a squad of formidable depth. And if coach Muricy Ramalho is under fire after a string of sub-par performances from his side, then nothing will boost morale more than a conclusive victory in the Morumbi stadium. The stakes are very high for both teams in this one.

Reigning champs San Lorenzo have a tricky match with a very talented Sao Paulo side.

Wednesday, Group 4

Emelec (Ecuador, 6 points) vs. Internacional (Brazil, 6 points)

Last week Inter ended Emelec's 100 percent record by coming from behind to win an exciting 3-2 win in Porto Alegre. Now they do battle again, though not in Emelec's home city of Guayaquil.

The club are carrying out work on their stadium, so this match will take place over 100 miles along the Pacific coast at Manta. Emelec, though, have a national following and will still have plenty of support. But they will no longer have coach Gustavo Quinteros on the sidelines.

Quinteros, who has presided over a very successful spell in the club's history, takes over this week in charge of the Ecuador national team. His replacement, Argentina's Omar De Felippe, is being thrown in the deep end against dangerous opponents -- through his mind may be eased by the likely absence though injury of two of Inter's star men, striker Nilmar and Argentine playmaker Andres D'Alessandro.

At the other end, Emelec's electric striker Miller Bolanos will be searching for holes in one of the leakiest defences in the tournament. Inter's Uruguayan coach Diego Aguirre seems to be considering a switch to a back three in a bid for more solidity -- a logical enough choice given the defensive deficiencies of his full-backs.

Thursday, Group 5

Palestino (Chile, 3 points) vs. Wanderers (Uruguay, 6 points)

With Boca Juniors of Argentina are almost home and dry after winning their first three games, this match will do much to determine who qualifies with them.

Last week in Montevideo, Wanderers came out on top, winning an attractive game 1-0. In fact, the boldness of little Wanderers' play has exceeded expectations in this competition. But Palestino have resources of their own, and coach Pablo Guede was big enough to admit that he had blundered in his planning for last week's match.

Palestino took the field with a back four. In the opening minutes, Wanderers repeatedly got behind their defence, and after conceding a first-half goal, Guede switched back to the team's more customary back three formation, after which the game was a more even affair. Thursday's meeting in Santiago promises plenty of drama.

Tim Vickery covers South American football for ESPN FC. Follow him on Twitter @Tim_Vickery.